
iiBusModuLes:sdRaMContRoLLeR(sdRaMC)
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ii-4-27
II
SDRAMC
0x301608:sdRaMRefreshRegister(psdRaMC_ReF)
name
address
Registername
Bit
Function
setting
init. R/W
Remarks
–
0x0to0x7F
–
seLdo
sCKon
seLen
seLCo6
seLCo5
seLCo4
seLCo3
seLCo2
seLCo1
seLCo0
–
auRCo11
auRCo10
auRCo9
auRCo8
auRCo7
auRCo6
auRCo5
auRCo4
auRCo3
auRCo2
auRCo1
auRCo0
D31–26
D25
D24
D23
D22
D21
D20
D19
D18
D17
D16
D15–12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
reserved
SDRAMself-refreshstatus
SDRAMclockduringself-refresh
SDRAMself-refreshenable
SDRAMself-refreshcounter
reserved
SDRAMauto-refreshcounter
–
0
1
–
0
1
0
1
0
–
R
R/W
–
R/W
0whenbeingread.
00301608
(W)
1 Refreshmode 0 Done
1 Enabled
0 Disabled
1 Enabled
0 Disabled
sdRaMrefresh
register
(pSDRAMC_REF)
–
0x0to0xFFF
d[31:26] Reserved
d25
seLdo:sdRaMself-RefreshstatusBit
This bit indicates the SDRAM self-refresh status.
1 (R):
In self-refresh mode
0 (R):
Not in self-refresh mode (default)
SELDO is 1 while the SDRAMC holds the SDCKE pin low (i.e., the SDRAM is in self-refresh mode).
Otherwise, SELDO = 0.
Before entering SLEEP mode, always be sure to read this bit using a program stored elsewhere (i.e., not
in the SDRAM) to confirm that the SDRAM is in self-refresh mode.
d24
sCKon:sdRaMClockenableduringself-RefreshBit
This bit selects whether to stop the SDRAM clock during self-refresh or not.
1 (R/W): Enable (not stopped)
0 (R/W): Disable (stopped) (default)
Writing 0 to SCKON causes the SDRAM clock output from the SDCLK pin to stop and to remain off
while the SDRAM is self-refreshed. This helps to reduce the chip's current consumption.
If SCKON = 1, the SDRAM clock is always output from the SDCLK pin even while the SDRAM is
self-refreshed.
d23
seLen:sdRaMself-RefreshenableBit
This bit enable the SDRAM's self-refresh control function.
1 (R/W): Enable
0 (R/W): Disable (default)
Writing 1 to SELEN enables the SDRAMC to start self-refreshing the SDRAM (by setting SDCKE
output low). Note that self-refreshing of the SDRAM actually begins a certain time after accessing or
auto-refreshing the SDRAM. The duration of this elapsed time is defined by the number of clock cycles
in SELCO[6:0] (D[22:16]). SELEN = 0 disables the self-refresh function.